1. Field of the Invention
The present invention relates to an optical disc drive, and more particularly, to an optical disc drive having a slideable tray installed in a main body.
2. Description of the Related Art
In general, an optical disc drive is a device which emits light on a disc-shaped optical medium (hereinafter, referred to as an optical disc), such as a CD (compact disc), DVD (digital versatile disc), or the like, to record information onto the optical disc or to read information from the optical disc.
FIG. 1 is a plan view illustrating one example of a conventional optical disc drive.
Referring to FIG. 1, a main body 50 including a main frame 10 and a deck portion 30 and a tray 20 are shown. The slideable tray 20 is installed at the main frame 10. Rails 11 are provided along the main frame 10 to guide a sliding motion of the tray 20. Usually, the rails 11 are formed integrally with the main frame 10. In addition, a loading motor 13 providing power to slide the tray 20, and a pinion gear 14 driven by the loading motor 13, are positioned on the main frame 10. A rack gear 22 connectable to the pinion gear 14 is positioned under the lower surface of the tray 20.
The deck portion 30 includes a spindle motor 31 to rotate a disc 90, and an optical pickup portion 32 to access the disc 90 while sliding in a radial direction of the disc 90. The deck portion 30 is installed on the main frame 10, and raised toward the lower surface of the disc 90 when the tray 20 is loaded, and lowered when the tray 20 is unloaded, by the action of a cam (not shown) mechanically connected to the loading motor 13.
Upon loading the disc 90, the disc 90 is mounted on a mounting surface 21 of the tray 20, and the loading motor 13 is rotated. The pinion gear 14 is then rotated, the rotational force of the pinion gear 14 is transmitted to the rack gear 22, and the tray 20 begins to slide. When the tray 20 is at least partially loaded, the deck portion 30 is raised. When the disc 90 is seated on a turntable 34 provided at the rotatable shaft of the spindle motor 31, the disc loading is completed. When the loading is completed, the disc 90 is rotated as the spindle motor 31 rotates. The optical pickup 32 accesses the disc 90 through a window 25 while sliding in the radial direction of the disc 90, to record information onto the disc 90 and/or reproduce information from the disc 90. The process of unloading the disc 90 is the reverse of the above-described loading process.
The tray 20 includes a mounting surface 21. The mounting surface 21 is an area on which the disc 90 is mounted, and has a circular recess stepped downward from the upper surface 24 of the tray 20. A diameter D1 of the mounting surface 21 is slightly longer than a diameter of the disc 90. The mounting surface 21 has a center portion concentric with the rotatable shaft of the spindle motor 31 when the tray 20 is loaded. When the disc 90 is mounted on the mounting surface 21, the outer circumference of the disc 90 is guided by the outmost circumferential wall of the mounting surface 21 stepped from the upper surface 24 of the tray 20, and the center of the disc 90 substantially coincides with that of the mounting surface 21. With this configuration, when the tray 20 is loaded, the disc 90 is stably seated on the turntable 34 since the center of the disc 90 substantially coincides with the rotatable shaft of the spindle motor 31.
However, recently, the disc 90 may vary in diameter. That is to say, in case of the CD, while a circular CD having a diameter of 120 mm is generally used, a circular CD having a diameter of 80 mm is also used. To accommodate the difference, the mounting surface 21 is formed to accommodate the circular CD having a diameter of 120 mm, and a second mounting surface 23 is formed to make a circular recess stepped downward from the mounting surface 21 so that the circular CD having a diameter of 80 mm can be used. Since CDs may have different diameters, with the conventional apparatus having stepped mounting surfaces 21 and 23 as in the conventional optical disc drive shown in FIG. 1, it is difficult to guide and stably seat circular CDs of various sizes on the turntable 34.
In addition, recent CDs are not only circular in shape. Discs of various shapes, such as a calling card shape, a flower shape, a Christmas tree shape, or the like, so-called fashion discs, are used. Since such fashion discs do not have a standard size and shape, with the conventional apparatus having the stepped mounting surfaces 21 and 23, as in the conventional optical disc drive shown in FIG. 1, it is difficult to guide and stably seat discs of various shapes on the turntable 34.
In addition, the optical disc drive may be installed as a vertical-type drive as shown in FIG. 2. To narrow the footprint of a computer, many half-height type optical disc drives are installed as vertical-type drives. In this case, a problem occurs in that the disc 90 cannot be properly seated on the turntable 34, since the disc 90 tends to move in the direction of arrow A in FIG. 2.
In an attempt order to properly seat the discs, hooking projections 26 may be formed to extend from the upper surface 24 of the tray 20 to the mounting surface 21 as shown in FIG. 2. However, such hooking projections 26 are only beneficial when the same size discs are used, and are not applicable when fashion discs having various sizes and shapes are used.